Description
When protecting CSS blocks with the nonce feature of Content Security Policy, the @import statement in the CSS block could allow an attacker to inject arbitrary styles, bypassing the intent of the Content Security Policy. This vulnerability affects Firefox < 74.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | unspecified – < 74 | 74 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | firefox | 74.0+build3-0ubuntu1 | — |
| Ubuntu 20.04 LTS | mozjs52 | No fix yet | — |
| Ubuntu 18.04 LTS | firefox | 74.0+build3-0ubuntu0.18.04.1 | USN-4299-1 |
| Ubuntu 18.04 LTS | mozjs38 +1 | No fix yet | — |
| Ubuntu 16.04 LTS | firefox | 74.0+build3-0ubuntu0.16.04.1 | USN-4299-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES 12 SP5 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SLES 12 SP4 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES 12 SP4 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SLES 12 SP3 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES 12 SP3 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SLES 12 SP2 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES 12 SP2 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
Show 11 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP5 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES for SAP 12 SP5 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SLES for SAP 12 SP4 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES for SAP 12 SP4 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SLES for SAP 12 SP3 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES for SAP 12 SP3 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SLES for SAP 12 SP2 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SLES for SAP 12 SP2 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud Crowbar 9 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud Crowbar 9 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud Crowbar 8 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud Crowbar 8 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud 9 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud 9 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud 8 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud 8 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud 7 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SUSE OpenStack Cloud 7 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SUSE HPE Helion OpenStack 8 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SUSE HPE Helion OpenStack 8 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
| SUSE Enterprise Storage 5 | MozillaFirefox | 78.0.1-112.3.1 | SUSE-SU-2020:1899-1 |
| SUSE Enterprise Storage 5 | MozillaFirefox-branding-SLE | 78-35.3.1 | SUSE-SU-2020:1899-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 92.0-1.2 | openSUSE-SU-2024:10600-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | librewolf | 74.0-r0 | — |
| Alpine v3.23 | firefox +1 | 74.0-r0 | — |
| Alpine v3.22 | firefox +1 | 74.0-r0 | — |
| Alpine v3.21 | firefox +1 | 74.0-r0 | — |
| Alpine v3.20 | firefox | 74.0-r0 | — |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | firefox | 74.0-r0 | — |
| Alpine v3.18 | firefox | 74.0-r0 | — |
| Alpine v3.17 | firefox | 74.0-r0 | — |
| Alpine v3.16 | firefox | 74.0-r0 | — |
| Alpine v3.15 | firefox | 74.0-r0 | — |
| Alpine v3.14 | firefox | 74.0-r0 | — |
| Alpine v3.13 | firefox | 74.0-r0 | — |
| Alpine v3.12 | firefox | 74.0-r0 | — |
Advisories 4
- USN-4299-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- SUSE-SU-2020:1899-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10600-1 MozillaFirefox-92.0-1.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:14572-1 firefox-esr-128.5.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026